Dismantlable injection syringe



INVENTOR. Amm DEAz A. DEBAZ DISMANTLABLE INJECTION SYRINGE Filed Oct. 23, 1955 April 8, 1958 United States Patent DISMANTLABLE INJECTION SYRINGE Andr Dbaz, Basel, Switzerland Application October 23, 1953, Serial No. 387,924 Claims priority, application Switzerland October 27, 1952 18 Claims. (Cl. 128--218) This invention relates to plunger-type injection syringes which can be dismantled. Syringes of this kind in which a cannula section fitted on the syringe cylinder and secured by means of a clamping device are already known for medical purposes. The syringe cylinder in such cases consists .of glass and ,is fixed in a metal fitting by which it is tightly enclosed. The said metal fitting consists of a metal sleeve which surrounds the glass cylinder and in which are milled wide longitudinal slots so that the contents of the syringe can be seen, said fitting having screwed thereon at each end a locking nut, one of said nuts .locking the cannula element in relation to the glass cylinder, while the other is fashioned as a cover for that end of the glass cylinder into which the plunger is introduced and accordingly comprises a central bore for passing the plunger rod therethrough.

This known type of construction has various disadvantages. In the first place, despite their comparatively large area,the said longitudinal slots in the metal sleeve still do not' permit of the contents of the syringe being apparent to the degree which is required in practice. More especially, thatend of the glass cylinder which is .connecteddirectly to the cannula element is covered by .the metal fitting, so that when drawing a liquid, for example, blood, into the syringe, the liquid entering the glass cylinder cannot be detected immediately at the commencement. It .is not possible to remove this disadvantage if it is desired to retain the said construction, since the threaded extension for the locking not .of the cannula element does .not permit the longitudinal slots in the metal sleeve being extended to the required extent. Moreover, the provision of locking nuts involves a comparatively large expenditure of metal and in addition results .ina correspondingly large external diameter of the fitting in the region of the locking nuts. .larly undesirable for the cannula end of the syringe,

This is particusince .it causes a compartively steep position of the syringe with respect .to the surface of the subject to be treated wheninserting the cannula fitted on to the syringe into the said subject for making an injection. On the contrary, however, it is desired in most cases that the insertion angle of the cannula should be as flat as possible, so that inorder in this case to obtain better conditions, the tendency has already been-tochange to constructions in which the cannulas are arranged eccentrically of the syringe axis.

The present invention now has for its object to obviate :these disadvantages and relates to a dismantable plungertype injection syringe having a cannula element which is fittedonthc syringe cylinder and which is held by means of a clamping device, characterised in that the clamping 2,329,643 Patented Apr. 8, 1958 ice Figure 1 is a central longitudinal section of one constructional form.

Figure 2 shows a cross-section thereof on the line lI--1I of Figure 1.

In the constructional form according to Figures 1 and 2, there is provided a syringe cylinder body 1 which is made of glass in the usual manner and is provided with an etched scale for indicating the contents of the syringe, the said cylinder having arranged therein in the usual manner a plunger 2 which is carried by a. plunger rod 3. The plunger rod 3 is provided at its free end in the usual manner with a handle. Fitted on a front end re ceiving portion of the cylinder 1 which .is remote from the handle is a cannula or nozzle element 4, which bears for a jointed movement in a manner known per se by means of a convex seating surface on a corresponding concave seating surface at the end of the cylinder 1. The cannula element 4 is formed with two diametrically opposed bores 5 which are arranged transversely of the axis of the syringe, one end of a connecting or tension member 6 beingfitted into each of the said bores. The two tension members 6, which are also diametrically opposed in relation to the axis of the syringe, consist of metal wire and are arranged in the middle main portion parallel to the syringe axis, the ends 7 thereof at the cannula end being bent over at an angle so that they each form a pin or projection which fits into the corresponding bore 5. The bending angle does not necessarily have to be a right angle, but it may in certain cases be expedient to use an abtuse angle in order to assure that the seating of the ends 7 in the bores 5 is obtained by spring effect when a pull is exerted on the tension 1nembers.

The other end of each tension member 6 is formed as an eye 8, through which is passed a hinge pin 9, the said pins being seated in the two limbs 10 of a clamping lever 11 forked at the end, so that each eye or lug 8 is pivotally connected to the associated clamping lever 11. Each clamping lever is mounted at the two lugs 13 of a common bearing member so as to be oscillatable or turnable about a turning axis constituted .by a bearing pin 12 parallel to the hinge axis of the lugs 8, it being clearly shown in Fig. 1 that the point at which each connecting member 6 is connected to its respective lever 11 is spaced from the point through which the turning axis of such lever 11 passes. The arrangement of the parts is such that the clamping levers are pivotable about axes which lie in a plane normal to the axis of the cylinder body 1 so that dtuing pivoting of these levers the tension members 6 will move in axial direction. Each pair oflugs 13 embraces the clamping lever. The bearing pin 12 is fashioned as a screw-bolt 14, which is introduced through a cylindrical bore of one of the bearing lugs and is screwed tightly into a coaxial threaded bore of the other bearing lug 13. The bearing member carrying the bearing lugs 13 consists of a sleeve 15 which surrounds the syringe cylinder 1 and which is provided at that end of the cylinder through which the plunger is inserted with an external thread 16 and an internal thread 17. The said end projects beyondthe cylinder 1 and is in engagement on the inside with a threaded sleeve 18 which fits snugly but rotatably on the end of the glass cylinder 1 and is thus supported axially in relation to the cylinder. The sleeve 18 is provided at the free end with a flange 19, the rim of which may be knurled in order to facilitate a better grip by the .handfor the purpose of turning the sleeve. As will be seen, the bearing sleeve 15 may "be adjusted by turning the sleeve 18 and thus there is produced a corresponding axial displacement of the bearing pins 12, in order .topermit the position of the latter to provided for this purpose is self-locking, the sleeve 15 is secured in each displaced position without special locking means being required for this purpose.

The rotatable threaded sleeve 18 is enclosed by a threaded cap 20, which is arranged on the external thread 16 of the'sleeve 18 and comprises a central opening 21 for the passage of the plunger rod 3. The threaded cap 20 therefore serves at the same time as a stroke limiting means for the piston 2.

As shown in Figure 1, the hinge pin 9 for the bearing pin 12 is so eccentrically arranged that each tension member 6 with the associated clamping lever 11 forms a crank drive which, in the clamping position shown in full lines in Figure l, is secured against undesired return travel by having passed beyond its intermediate or dead centre position. In this position, the two clamping levers 11 are directed at right-angles to the syringe axis and project laterally to such an extent that they can be used as finger grip supports for the operator, this clamping position of the two clamping levers being secured by one stop for each, said stops being formed by the free outer rim of the casing of threaded cap 20.

As will be seen, the two clamping levers ll accordingly form a clamping means connected to the cannula element 4 exclusively by the tension members 6, said clamping means being anchored by the two threaded sleeves 15 and 18 on that end of the syringe cylinder 1 through which the plunger is introduced, so that by rocking the clamping levers in the direction of the arrows 22 into the position 11' shown in broken lines in Figure 1, the tension members are relieved of tension, while a renewed tensioning or clamping eifect is obtained by swinging the clamping levers 11 in the opposite direction or sense. Thus, the clamping levers may be pivoted from the inoperative position shown at 11 to an intermediate or dead center position and from there to an operative or overcenter position in which inadverent turning of the clamping levers to the inoperative position is preventtd. This is so inasmuch as the point at which each connecting member 6 is attached to its respective lever 11 will, when the lever is in its dead center position, be spaced the maximum distance from the front end receiving portion of the body 1, whereas when the lever is in the position shown in solid lines the point in question is spaced from the front end receiving portion a distance which is materially smaller than the maximum distance and when the lever is in the position shown in dotted lines at 11' the point is spaced from the front end receiving portion a distance which is slightly smaller than the maximum distance. Consequently,

when the levers occupy the position shown in solid lines the nozzle member is clamped against the front end receiving portion whereas when the levers occupy the position shown in dotted lines the nozzle member will not be so clamped. Also, it will be seen that when the nozzle member is clamped against the front end receiving portion of the body 1, the levers 11 will, due to the tension of the connecting members 6, be biased for turning movement in a sense opposite to that indicated by the arrows 22, thereby preventing inadverent unclamping. The tensional force which is exerted on the tension members 6 and which is decisive for the bearing pressure of the cannula element 4 on the cylinder 1, is adapted to be regulated by the fact that after detachment of the threaded cap 20, the threaded sleeve 18 can be turned to the required extent in one or other direction, so that it is possible very accurately to produce the required bearing conditions in every case.

.cannula element is free.

As will be seen, apart from the relatively thin metal wires which form the tension members 6, the contents of the syringe can be seen from any side and as far as the base of the cannula, so that liquid drawn into the syringe is immediately visible upon entering the-cylinderl.

What I claim is:

1. In a dismantlable injection syringe, a cylinder, a plunger carried by a rod and displaceable longitudinally in said cylinder, a cannula element supported on the front end of said cylinder, at least two clamping levers pivotally mounted on the rear end of said cylinder, each of said clamping levers being connected by means of a tension member to said cannula element, said tension members being in a tensioned condition in one pivoted position of said clamping lever and in a detensioned condition in another pivoted position.

2. In a dismantlable injection syringe according 'to claim 1, said cannula element comprising bores disposed transversely of the cylinder axis and one end of each of said tension members releasably engaging in each of said bores.

3. In a dismantlable injection syringe according to claim 1, said clamping levers in the first-mentioned pivoted position forming fingergrips transversely of the cylinder axis for the hand of the operator.

4. In a dismantlable injection syringe according to claim 1, stop means for limiting the first-mentioned pivoted position of clamping levers arranged at the rear end of said cylinder.

5. In a dismantlable injection syringe according to claim 1, each of said clamping levers forming with the associated tension member a crank drive which, in the first-mentioned pivoted position of the clamping lever, locks against undesired release by passing beyond the dead center position.

6. In a dismantlable injection syringe according to claim 1, pivot pin means mounted on a common bearing member for supporting said clamping levers, said men1- ber bearing being displaceable parallel to the cylinder axis and being arranged to be secured in different positions of displacement.

7. In a dismantlable injection syringe, a plunger carried by a rod and displaceable longitudinally in the cylinder, a cannula element supponted at the front end of the said cylinder, a sleeve with an external thread rotatably mounted on the rear end of said cylinder, at second sleeve provided with an internal thread in engagement with the first-mentioned sleeve and mounted for longitudinal displacement on said cylinder, at least two clamping levers mounted to pivot on said second sleeve, each of said clamping levers being connected by means of a tension member to said cannula element, said tension members being in a tensioned condition in one pivoted position of said clamping levers and in an untensioned condition in another pivoted position, and the tension of said tension members being adjustable by turning the first-mentioned sleeve.

8. In a dismantlable injection syringe according to claim 7, a screw-threaded cap screwed on to said second-men: tioned sleeve, said cap surrounding said first-mentioned sleeve and being formed with a central bore for the passage of said plunger rod.

9. In a dismantlable injection syringe according to claim 7, a screw-tbreaded cap screwed on to said second-mentioned sleeve and comprising stops for limiting the pivotal movement of said clamping levers in the clamping position.

10. In a syringe, in combination, a cylindrical body member having a front end receiving portion; a nozzle member adapted to be received by said front end receiving portion of said body member; and clamping means for clamping said nozzle member to said body member when said nozzlemember is received by said receiving portion of said body member, said clamping means including at least one lever member pivotally mounted on said body member at a base portion thereof spaced from said front end receiving portion thereof for turningmovement about a turning axis lying in a plane substantially normal to the longitudinal axis of the cylindrical body member so that during turning movement of said lever member about said turning axis a point on said lever member moves in the direction of said longitudinal axis, and at least one connecting member connected to said nozzle member and to said lever member at said point thereof whereby said eonnectmg member may be moved toward said base portron of said body member during rotation of said lever member about said turning axis so that said nozzle member is clamped against said front end receiving portion of said body member.

11. The combination defined in claim 10, in which said lever member is turnable to and from an intermediate position wherein said point is spaced a maximum distance from said front end receiving portion of said body member and is turnable in a predetermined sense from an inoperative position wherein said point is spaced a first distance from said front end receiving portion of said body member, said first distance being materially smaller than said maximum distance so that said nozzle member is not clamped against said front end receiving portion of said body member, past said intermediate position to a clamping position wherein said point is spaced a see ond distance from said front end receiving portion of said body member, said second distance being slightly smaller than said maximum distance so that said nozzle member is clamped against said front end receiving portion of said body member whereby said lever member is biased for turning movement in said predetermined sense while said clamping means clamps said nozzle member against said front end receiving portion of said body member thereby preventing inadvertent turning movement of said lever member in the opposite sense.

12. The combination defined in claim 11, and stop means adapted to engage said lever member for preventing turning movement thereof in said predetermined sense when said lever member is in said clamping position thereof.

13. In a syringe, in combination, a cylindrical body member having a front end receiving portion; a nozzle member adapted to be received by said front end receiving portion of said body member; and clamping means for clamping said nozzle member to said body member when said nozzle member is received by said receiving portion of said body member, said clamping means ineluding two lever members each pivotally mounted diametrically opposite the other on said body member at a base portion thereof spaced from said front end receiving portion thereof for turning movement about a turning axis lying in a plane substantially normal to the longitudinal axis of the cylindrical body member so that during turning movement of each of said lever members about its respective turning axis a point on each of said lever members moves in the direction of said longitudinal axis, and two connecting members connected to said nozzle member and to each of said lever members, respectively, at said respective points thereof whereby said connecting member may be moved toward said base portion of said body member during rotation of said lever members about each respective turning axis so that said nozzle member is clamped against said front end receiving portion of said body member.

14. The combination defined in claim 13, in which each of said lever members is turnable to and from an intermediate position wherein said point thereon is spaced a maximum distance from said front end receiving portion of said body member and is tumable in a predetermined sense from an inoperative position wherein said point is spaced a first distance from said front end receiving portion of said body member, said first distance being materially smaller than said maximum distance so that said nozzle member is not clamped against said front end receiving portion of said body member, past said intermediate position to a clamping position wherein said point is spaced a second distance from said front end receiving portion of said body member, said second distance being slightly smaller than said maximum distance so that said nozzle member is clamped against said front end receiving portion of said body member whereby each of said lever members is biased for turning movement in said predetermined sense while said clamping means clamps said nozzle member against said. front end receiving portion of said body member thereby preventing inadvertent turning movement of said lever members in the opposite sense.

15. The combination defined in claim 14, and stop means adapted to engage each of said lever members for preventing turning movement thereof in said predetermined sense when each of said lever members is in said clamping position thereof.

16. The combination defined in claim 15 wherein said lever members in their respective clamping position emanate radially from said cylindrical body member so as to form finger grip means.

17. In a syringe, in combination, a cylindrical body member having a front end receiving portion; a nozzle member adapted to be received by said front end receiving portion of said body member; and clamping means for clamping said nozzle member to said body member when said nozzle member is received by said receiving portion of said body member, said clamping means including support means on said. body member in the region of a base portion thereof spaced from said front end receiving portion thereof, at least one lever member pivotally mounted on said support means for turning movement about a turning axis lying in a plane substantially normal to the longitudinal axis of the cylindrical body member so that during turning movement of said lever member about said turning axis a point on said lever member moves in the direction of said longitudinal axis, and at least one connecting member connected to said nozzle member and to said lever member at said point thereof whereby said connecting member may be moved toward said base portion of said body member during rotation of said lever member about said turning axis so that said nozzle member is clamped against said front end receiving portion of said! body member.

18. The combination defined in claim 17, said support means being movable relative to said body member in the direction of said longitudinal axis thereof whereby the force with which said nozzle member is clamped against said front end receiving portion of said body member may be varied.

References Cited in the file of this patent UNITED STATES PATENTS 562,425 Scheerer Jan. 23, 1896 1,157,552 Kispert Oct. 19, 1915 2,361,617 Everett Oct. 31, 1944 FOREIGN PATENTS 219,009 Great Britain Dec. 18, 1924 354,653 Germany June 12, 1922 1,027,526 France Feb. 18, 1953 

